锂离子电池电芯真空烘烤过程导热与水分蒸发的机理研究  

Simulation of Moisture Evaporation from Li-Ion Battery Cell in Baking at Low Vacuum

作　　者：关玉明[1,2] 姜钊[1,2] 赵芳华[1] 邱子桢 朱博[1] Guan Yuming Jiaang Zhao Zhao Fanghua Qiu Zizhen Zhu Bo(School of Mechanical Engineer, Hebei University of Technology, Tianjin 300130, China China Information Center for Lithium Energy Battery Equipment, Hebei University of Technology, Tianjin 300130, China)

机构地区：[1]河北工业大学机械工程学院,天津300130 [2]河北工业大学中国锂能电池装备网情报所,天津300130

出　　处：《真空科学与技术学报》2017年第9期862-865,共4页Chinese Journal of Vacuum Science and Technology

基　　金：天津市科技支撑项目(14JCTPJC00532)

摘　　要：锂离子电池电芯在注液前需进行真空烘烤去除水分,但在实际烘烤工作中无法对电芯的水分含量与温度变化进行实际测量,因此对烘烤的时间与工作温度选择具有盲目性,极易影响电芯质量甚至报废。针对电芯温度变化研究,可通过对烘烤过程进行傅里叶热传导定律分析计算,结果表明烘烤电芯位置与烤箱热源之间的距离和电芯温度变化呈阶梯分布,距离越近则温度升高越早,针对电芯内水分蒸发速率分析,可运用CFD仿真软件,通过加载由菲克定律计算得到的电芯水分扩散函数编译语言来仿真分析完成,结果表明电芯表面水分蒸发速率在烘烤10 min左右最快,而电芯底部在开始时水分蒸发速率很低,在50 min左右最快。95 min之后电芯的温度均到指定温度85℃,同时电芯水分去除完成。此研究对电芯烘烤的实际工作具有重要影响,对相似的真空烘烤工艺研究具有指导意义。The thermal evaporation of moisture,from Li-ion battery cell before solution injection,was physically modeled,theoretically analyzed in Fourier heat conduction law and Fick law,and numerically simulated with CFD software. The impact of the baking time on the evaporationrate,temperature and moisturedistributions was investigated. The simulated results show that the baking time in the initial stage significantly affects the evaporation rate,temperature and moisture content distributions. For example,baked at 85℃ for 10 min,the evaporation rate on the surface reaches the peak,and thenthe fairly low evaporation rateat and/or near the cell＇s bottom slowly increases to the peak after baking for another 40 min. Baking for 95 min uniformly heats up the whole cell to 85℃ and reliably reduces the moisture contentbelow the requirement. We suggest that the simulated results be of some technological interest in Li-ion battery cell fabrication.

关 键 词：锂电池电芯 水分蒸发 烘烤 FLUENT 

分 类 号：O551.3[理学—热学与物质分子运动论]